Vehicle cargo containers for transporting bulk material such as sawdust, gravel chip, cutter shavings and the like typically include open top boxes such as semi-trailers or the like defining side walls, a front wall, a rear wall and a floor. These open top containers are typically mechanically coupled to various types of vehicles such as cargo ships, railway carts and truck cabins for transporting goods between various locations.
During transportation in these so-called open top containers, there exists a substantial risk that a portion of the load may be blown out of the open top container by various physical phenomena such as vibration, aerodynamically created vacuum, wind or the like. If some of the load is accidentally blown out of the container it may potentially not only cause unnecessary wastage of the transported goods but may also create a dangerous situation.
For example, when the open-top container is attached to a truck cabin, some of the load accidentally blown out of the container may contaminate the road or highway as it whirls around thus causing dangerous ground road conditions. It may also be blown directly towards the windshield of following vehicles creating a potentially disastrous situation.
Accordingly, in many areas, regulations have been implemented for the carriage of various loads, particularly on public highways requiring that open top containers be provided with some type of covering structure for covering the loading aperture during transport. With the increasing number of accidents, these official requirements have become more and more stringent, sometimes requiring adequate coverage for the load on even short journeys.
Consequently, there has been an industry wide move to provide permanently installed flexible covers often referred to as tarpaulins or tarps that can be quickly rolled and unrolled by the driver so as to respectively allow selective uncovering and covering of the load. When these permanently installed tarpaulins are used only occasionally they may be stored on the vehicle in a folded condition and unfolded over the body as and when required.
Various configurations of tarpaulins have been proposed. However, two configurations have proven to be particularly popular. One such configuration is the so called end-rolled tarpaulin which is gathered at one of the longitudinal ends of the container when not in use and moved along the body of the container between operative and stored positions.
The end-rolled tarpaulins are typically gathered at the front end of the vehicle and are usually provided along their length with a number of transverse supporting bars which extend between the two longer side walls of the container. The end-rolled tarpaulins are typically moved by means of a pair of cables trained over pulleys and carrying the tarpaulins with them as they move. With such an arrangement, the movement of the tarpaulin typically moves the bows automatically out of the way so that the latter do not obstruct the re-loading through the top opening. The movement of the bows out of the way also reduces the risks of having the latter damaged by a new load.
The other type of permanently installed tarpaulins preferred by some haulers is commonly referred to as a side-rolled tarpaulin. The side-load tarpaulins typically, permanently extend the full length of the container body and are rolled and unrolled about a so-called rolling rod that also typically extends the full length of the container body.
Many devices exist for retracting an extending these tarpaulins. However, these devices are typically relatively complex. In addition, they often require that an intended user of the device climb onto the container onto which the tarpaulin retracting and extending device is positioned. This causes risks of injury to the intended user of these devices as the intended user may then fall from the container. In addition, these devices often require that the intended user perform movements in non-ergonomic positions, which may also lead to injuries.
In addition, in end-rolled tarpaulins, the bows typically slide over the top edge of the container. It often occurs that this top edge is damaged while the container is loaded. In these cases, the movement of the bows is not smooth, which may lead to problems in moving the tarpaulin between the retracted and operative configurations. In some cases, the bow may even drop off the edge of the container or the tarpaulin moving system may become damaged. Another disadvantage of these systems resides in that typically, the tarpaulin is not completely retracted from the top aperture when in the retracted configuration, which restricts access to the container. Yet another disadvantage of these systems resides in the bows are typically not linked to each other and are instead moved either by the tarpaulin as it is extended and retracted, or by the bows abutting against each other. This results in the creation of relatively large forces in the tarpaulin moving system, which requires that the whole system be built relatively robustly, with all the cost and weight disadvantages associated to a robust construction.
Against this background, there exists a need in the industry to provide a novel device for manipulating a tarpaulin.
An object of the present invention is therefore to provide a device for manipulating a tarpaulin.